Megastudies improve the impact of applied behavioural science.

Policy-makers are increasingly turning to behavioural science for insights about how to improve citizens' decisions and outcomes1. Typically, different scientists test different intervention ideas in different samples using different outcomes over different time intervals2. The lack of comparability of such individual investigations limits their potential to inform policy. Here, to address this limitation and accelerate the pace of discovery, we introduce the megastudy-a massive field experiment in which the effects of many different interventions are compared in the same population on the same objectively measured outcome for the same duration. In a megastudy targeting physical exercise among 61,293 members of an American fitness chain, 30 scientists from 15 different US universities worked in small independent teams to design a total of 54 different four-week digital programmes (or interventions) encouraging exercise. We show that 45% of these interventions significantly increased weekly gym visits by 9% to 27%; the top-performing intervention offered microrewards for returning to the gym after a missed workout. Only 8% of interventions induced behaviour change that was significant and measurable after the four-week intervention. Conditioning on the 45% of interventions that increased exercise during the intervention, we detected carry-over effects that were proportionally similar to those measured in previous research3-6. Forecasts by impartial judges failed to predict which interventions would be most effective, underscoring the value of testing many ideas at once and, therefore, the potential for megastudies to improve the evidentiary value of behavioural science.

Finding Positive Meaning in Negative Experiences Engages Ventral Striatal and Ventromedial Prefrontal Regions Associated with Reward Valuation.

Neuroimaging research has identified systems that facilitate minimizing negative emotion, but how the brain is able to transform the valence of an emotional response from negative to positive is unclear. Behavioral and psychophysiological studies suggest a distinction between minimizing reappraisal, which entails diminishing the arousal elicited by negative stimuli, and positive reappraisal, which instead changes the emotional valence of arousal from negative to positive. Here we show that successful minimizing reappraisal tracked with decreased activity in the amygdala, but successful positive reappraisal tracked with increased activity in regions involved in computing reward value, including the ventral striatum and ventromedial pFC (vmPFC). Moreover, positive reappraisal enhanced positive connectivity between vmPFC and amygdala, and individual differences in positive connectivity between vmPFC and amygdala, ventral striatum, dorsomedial pFC, and dorsolateral pFC predicted greater positive reappraisal success. These data broaden models of emotion regulation as quantitative dampening of negative emotion and identify activity in a network of brain valuation, arousal, and control regions as a neural basis for the ability to create positive meaning from negative experiences.

Concurrent and lasting effects of emotion regulation on amygdala response in adolescence and young adulthood.

This study used functional MRI (fMRI) to examine a novel aspect of emotion regulation in adolescent development: whether age predicts differences in both the concurrent and lasting effects of emotion regulation on amygdala response. In the first, active regulation, phase of the testing session, fMRI data were collected while 56 healthy individuals (age range: 10.50-22.92 years) reappraised aversive stimuli so as to diminish negative responses to them. After a short delay, the second, re-presentation, phase involved passively viewing the aversive images from the reappraisal task. During active regulation, older individuals showed greater drops in negative affect and inverse rostrolateral prefrontal-amygdala connectivity. During re-presentation, older individuals continued to show lasting reductions in the amygdala response to aversive stimuli they had previously reappraised, an effect mediated by rostrolateral PFC. These data suggest that one source of heightened emotionality in adolescence is a diminished ability to cognitively down-regulate aversive reactions.

Beyond direct reference: Comparing the present to the past promotes abstract processing.

A primary way that people make sense of their experience is by comparing various objects within their immediate environment to each other and to previously encountered objects. The objects involved in a comparison can be stimuli that are present within one's immediate environment, or mental representations of previously encountered stimuli that are now absent from one's immediate environment. In this research, we propose that the comparison process unfolds differently depending on whether an individual is comparing stimuli that are simultaneously present within a given context or is comparing a target stimulus to a stored representation of a previously encountered source stimulus. Across two studies, we found that people engage in more abstract processing when comparing a present stimulus to a previously encountered source than when comparing two simultaneously present stimuli. We discuss the implications of these findings for the role of abstraction in comparison and memory-based reasoning. (PsycINFO Database Record

Negative Autobiographical Memory in Depression Reflects Elevated Amygdala-Hippocampal Reactivity and Hippocampally Associated Emotion Regulation.

BACKGROUND: Dysregulated autobiographical recall is observed in major depressive disorder (MDD). However, it is unknown whether people with MDD show abnormalities in memory-, emotion-, and control-related brain systems during reactivity to and regulation of negative autobiographical memories. METHODS: We used functional magnetic resonance imaging to identify neural mechanisms underlying MDD-related emotional responses to negative autobiographical memories and the ability to downregulate these responses using a cognitive regulatory strategy known as reappraisal. We compared currently depressed, medication-free patients with MDD (n = 29) with control participants with no history of depression (n = 23). RESULTS: Relative to healthy control participants, medication-free MDD patients reported greater negative emotion during recall but relatively intact downregulation success. They also showed elevated amygdala activity and greater amygdala-hippocampal connectivity. This connectivity mediated the effect of MDD on negative emotional experience. When reappraising memories (vs. recalling from an immersed perspective), the MDD and control groups showed comparable recruitment of the prefrontal, parietal, and temporal cortices, and comparable downregulation of the amygdala and anterior hippocampus. However, MDD patients showed greater downregulation of the posterior hippocampus, and the extent of this downregulation predicted successful reduction of negative affect in MDD patients only. CONCLUSIONS: These data suggest amygdala-hippocampal connectivity and posterior hippocampal downregulation as brain mechanisms related to elevated emotional reactivity and atypical emotion regulation in MDD.

Affective lability and difficulties with regulation are differentially associated with amygdala and prefrontal response in women with Borderline Personality Disorder.

The present neuroimaging study investigated two aspects of difficulties with emotion associated with Borderline Personality Disorder (BPD): affective lability and difficulty regulating emotion. While these two characteristics have been previously linked to BPD symptomology, it remains unknown whether individual differences in affective lability and emotion regulation difficulties are subserved by distinct neural substrates within a BPD sample. To address this issue, sixty women diagnosed with BPD were scanned while completing a task that assessed baseline emotional reactivity as well as top-down emotion regulation. More affective instability, as measured by the Affective Lability Scale (ALS), positively correlated with greater amygdala responses on trials assessing emotional reactivity. Greater difficulties with regulating emotion, as measured by the Difficulties with Emotion Regulation Scale (DERS), was negatively correlated with left Inferior Frontal Gyrus (IFG) recruitment on trials assessing regulatory ability. These findings suggest that, within a sample of individuals with BPD, greater bottom-up amygdala activity is associated with heightened affective lability. By contrast, difficulties with emotion regulation are related to reduced IFG recruitment during emotion regulation. These results point to distinct neural mechanisms for different aspects of BPD symptomology.

Suicide attempters with Borderline Personality Disorder show differential orbitofrontal and parietal recruitment when reflecting on aversive memories.

Suicidal behavior and difficulty regulating emotions are hallmarks of Borderline Personality Disorder (BPD). This study examined neural links between emotion regulation and suicide risk in BPD. 60 individuals with BPD (all female, mean age = 28.9 years), 46 of whom had attempted suicide, completed a fMRI task involving recalling aversive personal memories. Distance trials assessed the ability to regulate emotion by recalling memories from a third-person, objective viewpoint. Immerse trials assessed emotional reactivity and involved recalling memories from a first-person perspective. Behaviorally, both groups reported less negative affect on Distance as compared to Immerse trials. Neurally, two sets of findings were obtained. The first reflected differences between attempters and non-attempters. When immersing and distancing, attempters showed elevated recruitment of lateral orbitofrontal cortex, a brain region implicated in using negative cues to guide behavior. When distancing, attempters showed diminished recruitment of the precuneus, a region implicated in memory recall and perspective taking. The second set of findings related to individual differences in regulation success - the degree to which individuals used distancing to reduce negative affect. Here, we observed that attempters who successfully regulated exhibited precuneus recruitment that was more similar to non-attempters. These data provide insight into mechanisms underlying suicide attempts in BPD. Future work may examine if these findings generalize to other diagnoses and also whether prior findings in BPD differ across attempters and non-attempters.